Polyolefin composition including hollow glass microspheres and method of using the same

ABSTRACT

A composition that includes a polyolefin having first repeating units, hollow glass microspheres, a polyolefin impact modifier that is chemically non-crosslinked and free of polar functional groups, and a compatibilizer comprising the first repeating units and second repeating units, which are the first repeating units modified with polar functional groups. Articles made from the composition and methods of making an article by injection molding the composition are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No.61/921,848, filed Dec. 30, 2013, the disclosure of which is incorporatedby reference in its entirety herein.

BACKGROUND

Hollow glass microspheres having an average diameter of less than about500 micrometers, also commonly known as “glass microbubbles”, “glassbubbles”, “hollow glass beads”, or “glass balloons” are widely used inindustry, for example, as additives to polymeric compositions. In manyindustries, hollow glass microspheres are useful, for example, forlowering weight and improving processing, dimensional stability, andflow properties of a polymeric composition. Generally, it is desirablethat the hollow glass microspheres be strong enough to avoid beingcrushed or broken during processing of the particular polymericcompound. Hollow glass microspheres have been incorporated intopolypropylene compositions for certain applications. See, for example,U.S. Pat. No. 7,365,144 (Ka et al.).

SUMMARY

In one aspect, the present disclosure provides a composition includingor consisting of a polyolefin comprising first repeating units, hollowglass microspheres, a polyolefin impact modifier that is chemicallynon-crosslinked and free of polar functional groups, and acompatibilizer comprising the first repeating units and second repeatingunits, which are the first repeating units modified with polarfunctional groups. The hollow glass microspheres are present in a rangefrom 40% to 70% by volume, the polyolefin impact modifier is present ina range from 20% to 50% by volume, and the compatibilizer is present ina range from 4% to 12% by volume, based on the total volume of thehollow glass microspheres, the polyolefin impact modifier, and thecompatibilizer. The composition typically includes greater than tenpercent by weight of the glass, based on the total weight of thecomposition, which glass may be included in the hollow glassmicrospheres or non-spherical glass including broken microspheres.

In some embodiments of this aspect, the polyolefin is other than apolypropylene homopolymer. In some embodiments, the composition has amelt flow index at 190° C. and 2.16 kilograms of at least 3 grams per 10minutes. In some embodiments, the composition has a notched izod impactstrength of at least 60 joules/meter. In some embodiments, thepolyolefin comprises polyethylene, and the compatibilizer comprisesethylene repeating units. In some embodiments, the first repeating unitsare polypropylene repeating units, and the compatibilizer comprisespropylene repeating units. In these embodiments, the polyolefin may be acopolymer comprising at least 80% by weight propylene units. In theseembodiments, the polyolefin may be a medium or high impactpolypropylene.

In another aspect, the present disclosure provides an article comprisingsuch a composition when it is solidified.

In another aspect, the present disclosure provides a masterbatchcomposition for combining with a polyolefin comprising first repeatingunits. The masterbatch comprises includes hollow glass microspheres, apolyolefin impact modifier that is chemically non-crosslinked and freeof polar functional groups, and a compatibilizer comprising the firstrepeating units and second repeating units modified with polarfunctional groups. In some embodiments, the masterbatch compositioncontains the polyolefin comprising first repeating units. In otherembodiments, the masterbatch composition does not contain the polyolefincomprising first repeating units. The hollow glass microspheres arepresent in a range from 40% to 65% by volume, the polyolefin impactmodifier is present in a range from 20% to 50% by volume, and thecompatibilizer is present in a range from 4% to 15% by volume, based onthe total volume of the hollow glass microspheres, the polyolefin impactmodifier, and the compatibilizer.

In another aspect, the present disclosure provides a method of making anarticle, the method comprising injection molding the compositiondescribed above to make the article.

The compositions according to the present disclosure are suitable, forexample, for injection molding to prepare relatively low densityarticles typically having good tensile, flexural, and impact strength.For the composition disclosed herein, in many embodiments, at least oneof the impact strength (e.g., in some cases, either notched or unnotchedimpact strength), tensile strength, or flexural strength of thecompositions according to the present disclosure approach or in somecases even surprisingly exceed the impact strength of the polyolefinwithout the addition of hollow glass microspheres. Surprisingly, thisimprovement was not observed or was not as significant when thecompatibilizer included repeating units different from the firstrepeating units.

In this application, terms such as “a”, “an” and “the” are not intendedto refer to only a singular entity, but include the general class ofwhich a specific example may be used for illustration. The terms “a”,“an”, and “the” are used interchangeably with the term “at least one”.The phrases “at least one of” and “comprises at least one of” followedby a list refers to any one of the items in the list and any combinationof two or more items in the list. All numerical ranges are inclusive oftheir endpoints and non-integral values between the endpoints unlessotherwise stated.

The term “crosslinked” refers to joining polymer chains together bycovalent chemical bonds, usually via crosslinking molecules or groups,to form a network polymer. Therefore, a chemically non-crosslinkedpolymer is a polymer that lacks polymer chains joined together bycovalent chemical bonds to form a network polymer. A crosslinked polymeris generally characterized by insolubility, but may be swellable in thepresence of an appropriate solvent. A non-crosslinked polymer istypically soluble in certain solvents and is typically melt-processable.A polymer that is chemically non-crosslinked may also be referred to asa linear polymer.

A polar functional group is a functional group that includes at leastone atom that is more electronegative than carbon. Common elements oforganic compounds that are more electronegative than carbon are oxygen,nitrogen, sulfur, and halogens. In some embodiments, a polar functionalgroup is a functional group that includes at least one oxygen atom. Suchgroups include hydroxyl and carbonyl groups (e.g., such as those inketones, aldehydes, carboxylic acids, carboxyamides, carboxylic acidanhydrides, and carboxylic acid esters).

The above summary of the present disclosure is not intended to describeeach disclosed embodiment or every implementation of the presentdisclosure. The description that follows more particularly exemplifiesillustrative embodiments. It is to be understood, therefore, that thefollowing description should not be read in a manner that would undulylimit the scope of this disclosure.

DETAILED DESCRIPTION

Addition of hollow glass microspheres into a polyolefin such as apolypropylene or high density polyethylene renders them lightweight butusually adversely affects impact strength, tensile strength, andflexural strength. Impact strength, tensile strength, and flexuralstrength are all attributes of the polyolefin phase, and the addition ofhollow glass microspheres dilutes the polyolefin phase. Also, theaddition of hollow glass microspheres typically increases viscosityrelative to an unfilled polyolefin. An increase in viscosity is adisadvantage, particularly for some polymer processing techniques (e.g.,injection molding).

Impact modifiers, which are typically elastomeric materials, arecommonly used in polyolefin compositions and can be useful to compensatefor the loss in impact strength that accompanies the addition of hollowglass microspheres. Although impact properties can be improved by theaddition of impact modifiers, impact modifiers also tend to decrease thetensile and flexural strength of polyolefins. For composites ofpolyolefins and hollow glass microspheres including impact modifiers,the tensile strength and flexural strength are typically greatly reducedrelative to the initial polyolefin due to dilution of thestrength-inducing polymer phase as described above and the presence ofthe soft, rubbery impact modifier. Many impact modifiers are highviscosity, high molecular weight rubbery materials that increase theviscosity of a composition, which is disadvantageous for some polymerprocessing techniques. Since both the addition of hollow glassmicrospheres and impact modifiers increase viscosity, impact-modified,polyolefin-hollow glass microsphere composites with viscosities suitablefor injection molding, for example, are difficult to achieve.

We have found that the simultaneous use of a polyolefin impact modifierthat is chemically non-crosslinked and free of polar functional groupsand a compatibilizer comprising repeating units modified with polarfunctional groups in addition to repeating units that are the same as amatrix polyolefin in a composition increases the impact strength moreefficiently than other combinations of impact modifiers andcompatibilizers while also providing a tensile strength and a flexuralstrength in the composition that can approach or even exceed, in somecases, the tensile strength and flexural strength of the matrixpolyolefin alone. As described above, higher impact strength typicallycomes at the expense of lowering the tensile and flexural strength.While not wanting to be bound by theory, it is believed that thefunctional compatibilizers in which the functional groups are graftedonto a main polymer chain that is the same as the matrix polymer canco-crystallize with the polymer phase, which can lead to an improvementin impact, tensile, and flexural strength. The chemicallynon-crosslinked impact modifier that is free of polar functional groupsand the polyolefin providing the matrix of the composition can beselected to have low viscosities, thus providing a composition that islight-weight, has excellent impact, tensile, and flexural strength, andis well suited to injection molding.

While including hollow glass microspheres in polymeric compositions canprovide many benefits, the process of adding glass bubbles into apolymer in a manufacturing process can pose some challenges. Handlingglass bubbles may be similar to handling light powders. The hollow glassmicrospheres may not be easily contained and difficult to use in a cleanenvironment. It can also be difficult to add an accurate amount ofhollow glass microspheres to the polymer. Therefore, the presentdisclosure provides a masterbatch composition useful, for example, forincorporating hollow glass microspheres into a final, end-use injectionmoldable thermoplastic composition. Delivering the hollow glassmicrospheres in a masterbatch composition can eliminate at least some ofthe handling difficulties encountered during manufacturing.

Examples of polyolefins useful for the compositions according to thepresent disclosure include those made from monomers having the generalstructure CH₂═CHR¹⁰, wherein R¹⁰ is a hydrogen or alkyl. In someembodiments, R¹⁰ having up to 10 carbon atoms or from one to six carbonatoms. The first repeating units of such polyolefins would have thegeneral formula —[CH₂—CHR¹⁰]—, wherein R¹⁰ is defined as in any of theaforementioned embodiments. Examples of suitable polyolefins includepolyethylene; polypropylene; poly (1-butene); poly (3-methylbutene; poly(4-methylpentene); copolymers of ethylene with propylene, 1-butene,1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene, and 1-octadecene; andblends of polyethylene and polypropylene. Typically, the compositionsaccording to the present disclosure comprise at least one ofpolyethylene or polypropylene. It should be understood that a polyolefincomprising polyethylene may be a polyethylene homopolymer or a copolymercontaining ethylene repeating units. Similarly, it should be understoodthat a polyolefin comprising polypropylene may be a polypropylenehomopolymer or a copolymer containing propylene repeating units. Thepolyolefin comprising at least one of polyethylene or polypropylene mayalso be part a blend of different polyolefins that includes at least oneof polypropylene or polyethylene. Useful polyethylene polymers includehigh density polyethylene (e.g., those having a density of such as from0.94 to about 0.98 g/cm₃) and linear or branched low-densitypolyethylenes (e.g. those having a density of such as from 0.89 to 0.94g/cm₃). Useful polypropylene polymers include low impact, medium impact,or high impact polypropylene. A high impact polypropylene may be acopolymer of polypropylene including at least 80, 85, 90, or 95% byweight propylene repeating units, based on the weight of the copolymer.In these embodiments, it should be understood that the first repeatingunits are those most abundant in the copolymer. The polyolefin maycomprise mixtures of stereo-isomers of such polymers (e.g., mixtures ofisotactic polypropylene and atactic polypropylene). Suitablepolypropylene can be obtained from a variety of commercial sources, forexample, LyondellBasell, Houston, Tex., under the trade designations“PRO-FAX” and “HIFAX”, and from Pinnacle Polymers, Garyville, La., underthe trade designation “PINNACLE”. In some embodiments, the firstrepeating units in the polyolefin are propylene repeating units. In someembodiments, the repeating units in the polyolefin consist of propylenerepeating units. In some embodiments, the first repeating units in thepolyolefin are ethylene repeating units. In some embodiments, thepolyolefin is a polyethylene. In some embodiments, the repeating unitsin the polyolefin consist of ethylene repeating units. In someembodiments, the polyethylene is high density polyethylene. Suitablepolyethylene can be obtained from a variety of commercial sources, forexample, Braskem S. A., Sao Paolo, Brazil.

The polyolefin may be selected to have a relatively low viscosity asmeasured by melt flow index. In some embodiments, the polyolefin has amelt flow index at 230° C. and 2.16 kilograms of at least 3 grams per 10minutes (in some embodiments, at least 5, 10, 15, 20, 25, 30, 35, 40, or50 grams per 10 minutes). The melt flow index of the polyolefin ismeasured by ASTM D1238-13: Standard Test Method for Melt Flow Rates ofThermoplastics by Extrusion Plastometer.

In the final (e.g., let-down) composition suitable for injection moldingarticles, the polyolefin comprising first repeating units is typicallythe major component of the compositions according to the presentdisclosure and/or useful in the methods according to the presentdisclosure. In general, the polyolefin provides at least 50 percent byweight, based on the total weight of the composition. In someembodiments, the polyolefin comprising first repeating units is presentin a range from 50 percent to 75 percent, 55 percent to 70 percent, or60 percent to 70 percent by weight, based on the total weight of thecomposition.

A masterbatch composition according to the present disclosure, may ormay not contain the polyolefin comprising first repeating units. In someembodiments, the masterbatch comprises the polyolefin comprising thefirst repeating units, but at a lower percentage than in the let-downcompositions suitable for injection molding described above. In someembodiments, the masterbatch comprises the polyolefin in an amount up to5, 4, 3, or 2 percent by weight, based on the total weight of themasterbatch. The process of combining a masterbatch with othercompatible materials is commonly referred to as “letting down” themasterbatch. In the present disclosure, the composition that is madefrom the masterbatch can also be referred to as the let-downcomposition. A composition useful for letting down a masterbatchcomposition typically includes the polyolefin in a sufficient amount tomake the let-down composition described above.

The compatibilizer includes the same repeating units, which are thefirst repeating units, as the polyolefin in the compositions accordingto the present disclosure. The compatibilizer also includes secondrepeating units, which are the first repeating units modified with polarfunctional groups. In some embodiments, the polar functional groupsinclude maleic anhydride, carboxylic acid groups, and hydroxyl groups.In some embodiments, the compatibilizer is a maleic anhydride-modifiedpolyolefin. When the polyolefin in the composition comprisespolypropylene, the compatibilizer is a maleic anhydride-modifiedpolypropylene. When the polyolefin in the composition comprisespolyethylene, the compatibilizer is a maleic anhydride-modifiedpolyethylene. The compatibilizer is added to the composition in anamount sufficient to improve the mechanical properties of thecomposition. The level of grafting of the polar functional groups (e.g.,the level of grafting of maleic anhydride in the modified polyolefin maybe in a range from about 0.5-3%, 0.5-2%, 0.8-1.2%, or about 1%).

In a let-down composition, the compatibilizer may be present in thecomposition in an amount greater than two percent, based on the totalweight of the composition. In some embodiments, compatibilizer ispresent in the composition in amount of at least 2.5, 3, 3.5, or 4percent, based on the total weight of the composition. In a let-downcomposition, the compatibilizer may be present in the composition in anamount greater than 1.5 percent, based on the total volume of thecomposition. In some embodiments, compatibilizer is present in thecomposition in amount of at least in a range from 1.5 percent to 4percent or 2 percent to 4 percent, based on the total volume of thecomposition.

In a masterbatch composition, the compatibilizer may be present in arange from 4% to 15% by volume, in some embodiments, 10% to 15% byvolume, based on the total volume of the masterbatch composition. Acomposition for letting down the masterbatch may also include 4% to 15%by volume, in some embodiments, 10% to 15% by volume compatibilizer,based on the total weight of the composition for letting down themasterbatch.

Example 12, below, describes a polypropylene composition that includes apolypropylene compatibilizer. In comparison to Comparative Example 7E,when the compatibilizer is made from a polyethylene, and therefore doesnot have the same first repeating units as the polypropylene, thecomposition has inferior notched impact strength, tensile strength, andflexural strength than when the compatibilizer comprises polypropylenerepeating units (that is, the same first repeating units as thepolyolefin). The effect is even more pronounced for a higher impactpolypropylene as shown by a comparison of Example 30 and ComparativeExample 15A in Table 19 and for a high density polyethylene as shown bya comparison of Example 3 and Comparative Example 1B in Table 4. Incomparison to Comparative Example 1B, when the compatibilizer is madefrom a polypropylene, and therefore does not have the same firstrepeating units as the polyethylene, the composition has inferiortensile strength and flexural strength and far inferior notched impactstrength than when the compatibilizer comprises polyethylene repeatingunits (that is, the same first repeating units as the polyolefin).

The impact modifier also is a polyolefin, is chemically non-crosslinked,and is free of polar functional groups. For example, the impact modifieris free of any of the polar functional groups described above inconnection with the compatibilizer. In some embodiments, the impactmodifier includes only carbon-carbon and carbon-hydrogen bonds. In someembodiments, the polyolefin impact modifier is an ethylene propyleneelastomer, an ethylene octene elastomer, an ethylene propylene dieneelastomer, an ethylene propylene octene elastomer, polybutadiene, abutadiene copolymer, polybutene, or a combination thereof. In someembodiments, the polyolefin impact modifier is an ethylene octeneelastomer.

The impact modifier may be selected to have a relatively low viscosityas measured by melt flow index. A combination of impact modifiers havingdifferent melt flow indexes may also be useful. In some embodiments, atleast one of the polyolefin impact modifiers has a melt flow index at190° C. and 2.16 kilograms of at least 10 grams per 10 minutes (in someembodiments, at least 11, 12, or 13 grams per 10 minutes). The melt flowindex of the impact modifiers and the polyolefin is measured by ASTMD1238-13: Standard Test Method for Melt Flow Rates of Thermoplastics byExtrusion Plastometer.

Other common types of impact modifiers such as ground rubber, core-shellparticles, functionalized elastomers available, for example, from DowChemical Company, Midland, Mich., under the trade designation “AMPLIFYGR-216”, and particles available, for example, from Akzo Nobel,Amsterdam, The Netherlands, under the trade designation “EXPANCEL” areat least one of chemically crosslinked or functionalized and are notincluded in the compositions according to the present disclosure. Manyof these impact modifiers increase the viscosity of a composition,making the composition less suitable for some polymer processingtechniques (e.g., injection molding). In addition, “EXPANCEL” particlesand similar particles require more strict thermal control and moreprecise handling than the polyolefin impact modifiers described herein,which can present challenges during processing.

The impact modifier can be added to the composition according to thepresent disclosure in an amount sufficient to improve the impactstrength of the composition.

In a let-down composition, the impact modifier may be present in thecomposition in a range from 7.5 percent to 25 percent by volume, basedon the total volume of the composition. In some embodiments, impactmodifier is present in the composition in amount of at least 10, 12, 14,15, or 16 percent and up to about 20 percent by volume, based on thetotal volume of the composition. Less impact modifier may be requiredwith a lower level of hollow glass microspheres. A composition forletting down a masterbatch may also include the impact modifier in anysuitable range (e.g., any of the ranges described above) depending onthe desired final composition.

In a masterbatch composition, the impact modifier may be present in thecomposition in a range from 50 percent to 75 percent by volume, based onthe total volume of the composition. In some embodiments, impactmodifier is present in the masterbatch composition in amount of at least50, 55, or 60 percent and up to about 65, 70, or 75 percent by volume,based on the total volume of the composition. In some embodiments of amasterbatch composition, the impact modifier is present in a range from60 to 70 percent by volume, based on the total volume of thecomposition.

Hollow glass microspheres useful in the compositions and methodsaccording to the present disclosure can be made by techniques known inthe art (see, e.g., U.S. Pat. No. 2,978,340 (Veatch et al.); U.S. Pat.No. 3,030,215 (Veatch et al.); U.S. Pat. No. 3,129,086 (Veatch et al.);and U.S. Pat. No. 3,230,064 (Veatch et al.); U.S. Pat. No. 3,365,315(Beck et al.); U.S. Pat. No. 4,391,646 (Howell); and U.S. Pat. No.4,767,726 (Marshall); and U. S. Pat. App. Pub. No. 2006/0122049(Marshall et. al). Techniques for preparing hollow glass microspherestypically include heating milled frit, commonly referred to as “feed”,which contains a blowing agent (e.g., sulfur or a compound of oxygen andsulfur). Frit can be made by heating mineral components of glass at hightemperatures until molten glass is formed.

Although the frit and/or the feed may have any composition that iscapable of forming a glass, typically, on a total weight basis, the fritcomprises from 50 to 90 percent of SiO₂, from 2 to 20 percent of alkalimetal oxide, from 1 to 30 percent of B₂O₃, from 0.005-0.5 percent ofsulfur (for example, as elemental sulfur, sulfate or sulfite), from 0 to25 percent divalent metal oxides (for example, CaO, MgO, BaO, SrO, ZnO,or PbO), from 0 to 10 percent of tetravalent metal oxides other thanSiO₂ (for example, TiO₂, MnO₂, or ZrO₂), from 0 to 20 percent oftrivalent metal oxides (for example, Al₂O₃, Fe₂O₃, or Sb₂O₃), from 0 to10 percent of oxides of pentavalent atoms (for example, P₂O₅ or V₂O₅),and from 0 to 5 percent fluorine (as fluoride) which may act as afluxing agent to facilitate melting of the glass composition. Additionalingredients are useful in frit compositions and can be included in thefrit, for example, to contribute particular properties orcharacteristics (for example, hardness or color) to the resultant glassbubbles.

In some embodiments, the hollow glass microspheres useful in thecompositions and methods according to the present disclosure have aglass composition comprising more alkaline earth metal oxide than alkalimetal oxide. In some of these embodiments, the weight ratio of alkalineearth metal oxide to alkali metal oxide is in a range from 1.2:1 to 3:1.In some embodiments, the hollow glass microspheres have a glasscomposition comprising B₂O₃ in a range from 2 percent to 6 percent basedon the total weight of the glass bubbles. In some embodiments, thehollow glass microspheres have a glass composition comprising up to 5percent by weight Al₂O₃, based on the total weight of the hollow glassmicrospheres. In some embodiments, the glass composition is essentiallyfree of Al₂O₃. “Essentially free of Al₂O₃” may mean up to 5, 4, 3, 2, 1,0.75, 0.5, 0.25, or 0.1 percent by weight Al₂O₃. Glass compositions thatare “essentially free of Al₂O₃” also include glass compositions havingno Al₂O₃. Hollow glass microspheres useful for practicing the presentdisclosure may have, in some embodiments, a chemical composition whereinat least 90%, 94%, or even at least 97% of the glass comprises at least67% SiO₂, (e.g., a range of 70% to 80% SiO₂), a range of 8% to 15% of analkaline earth metal oxide (e.g., CaO), a range of 3% to 8% of an alkalimetal oxide (e.g., Na₂O), a range of 2% to 6% B₂O₃, and a range of0.125% to 1.5% SO₃. In some embodiments, the glass comprises in a rangefrom 30% to 40% Si, 3% to 8% Na, 5% to 11% Ca, 0.5% to 2% B, and 40% to55% 0, based on the total of the glass composition.

The “average true density” of hollow glass microspheres is the quotientobtained by dividing the mass of a sample of hollow glass microspheresby the true volume of that mass of hollow glass microspheres as measuredby a gas pycnometer. The “true volume” is the aggregate total volume ofthe hollow glass microspheres, not the bulk volume. The average truedensity of the hollow glass microspheres useful for practicing thepresent disclosure is generally at least 0.30 grams per cubic centimeter(g/cc), 0.35 g/cc, or 0.38 g/cc. In some embodiments, the hollow glassmicrospheres useful for practicing the present disclosure have anaverage true density of up to about 0.65 g/cc. “About 0.65 g/cc” means0.65 g/cc±five percent. In some of these embodiments, the average truedensity of the hollow glass microspheres is up to 0.6 g/cc or 0.55 g/cc.For example, the average true density of the hollow glass microspheresdisclosed herein may be in a range from 0.30 g/cc to 0.65 g/c, 0.30 g/ccto 0.6 g/cc, 0.35 g/cc to 0.60 g/cc, or 0.35 g/cc to 0.55 g/cc. Hollowglass microspheres having any of these densities can be useful forlowering the density of the composition according to the presentdisclosure, relative to polyolefin compositions that do not containhollow glass microspheres.

For the purposes of this disclosure, average true density is measuredusing a pycnometer according to ASTM D2840-69, “Average True ParticleDensity of Hollow Microspheres”. The pycnometer may be obtained, forexample, under the trade designation “ACCUPYC 1330 PYCNOMETER” fromMicromeritics, Norcross, Ga., or under the trade designations“PENTAPYCNOMETER” or “ULTRAPYCNOMETER 1000” from Formanex, Inc., SanDiego, Calif. Average true density can typically be measured with anaccuracy of 0.001 g/cc. Accordingly, each of the density values providedabove can be ±five percent.

A variety of sizes of hollow glass microspheres may be useful. As usedherein, the term size is considered to be equivalent with the diameterand height of the hollow glass microspheres. In some embodiments, thehollow glass microspheres can have a median size by volume in a rangefrom 14 to 45 micrometers (in some embodiments from 15 to 40micrometers, 20 to 45 micrometers, or 20 to 40 micrometers). The mediansize is also called the D50 size, where 50 percent by volume of thehollow glass microspheres in the distribution are smaller than theindicated size. For the purposes of the present disclosure, the mediansize by volume is determined by laser light diffraction by dispersingthe hollow glass microspheres in deaerated, deionized water. Laser lightdiffraction particle size analyzers are available, for example, underthe trade designation “SATURN DIGISIZER” from Micromeritics. The sizedistribution of the hollow glass microspheres useful for practicing thepresent disclosure may be Gaussian, normal, or non-normal. Non-normaldistributions may be unimodal or multi-modal (e.g., bimodal).

The hollow glass microspheres useful in the compositions and methodsaccording to the present disclosure typically need to be strong enoughto survive the injection molding process. A useful hydrostatic pressureat which ten percent by volume of the hollow glass microspherescollapses is at least about 20 (in some embodiments, at least about 38,50, or 55) megapascals (MPa). “About 20 MPa” means 20 MPa±five percent.In some embodiments, a hydrostatic pressure at which ten percent byvolume of the hollow glass microspheres collapses can be at least 100,110, or 120 MPa. In some embodiments, a hydrostatic pressure at whichten percent, or twenty percent, by volume of the hollow glassmicrospheres collapses is up to 250 (in some embodiments, up to 210,190, or 170) MPa. The hydrostatic pressure at which ten percent byvolume of hollow glass microspheres collapses may be in a range from 20MPa to 250 MPa, 38 MPa to 210 MPa, or 50 MPa to 210 MPa. For thepurposes of the present disclosure, the collapse strength of the hollowglass microspheres is measured on a dispersion of the hollow glassmicrospheres in glycerol using ASTM D3102-72 “Hydrostatic CollapseStrength of Hollow Glass Microspheres”; with the exception that thesample size (in grams) is equal to 10 times the density of the glassbubbles. Collapse strength can typically be measured with an accuracy of±about five percent. Accordingly, each of the collapse strength valuesprovided above can be ±five percent.

Hollow glass microspheres useful for practicing the present disclosurecan be obtained commercially and include those marketed by 3M Company,St. Paul, Minn., under the trade designation “3M GLASS BUBBLES” (e.g.,grades S60, S60HS, iM30K, iM16K, S38HS, S38XHS, K42HS, K46, andH50/10000). Other suitable hollow glass microspheres can be obtained,for example, from Potters Industries, Valley Forge, Pa., (an affiliateof PQ Corporation) under the trade designations “SPHERICEL HOLLOW GLASSSPHERES” (e.g., grades 110P8 and 60P18) and “Q-CEL HOLLOW SPHERES”(e.g., grades 30, 6014, 6019, 6028, 6036, 6042, 6048, 5019, 5023, and5028), from Silbrico Corp., Hodgkins, Ill. under the trade designation“SIL-CELL” (e.g., grades SIL 35/34, SIL-32, SIL-42, and SIL-43), andfrom Sinosteel Maanshan Inst. of Mining Research Co., Maanshan, China,under the trade designation “Y8000”. In some embodiments, hollow glassmicrospheres useful for practicing the present disclosure may beselected to have crush strengths of at least about 28 MPa, 34 MPa, 41MPa, 48 MPa, or 55 MPa for 90% survival.

In a let-down (i.e., final) composition suitable for injection molding,for example, the hollow glass microspheres are typically present in thecomposition disclosed herein at a level of at least 5 percent by weight,based on the total weight of the composition. In some embodiments, thehollow glass microspheres are present in the composition at least at 10,12, or 13 percent by weight based on the total weight of thecomposition. In some embodiments, the hollow glass microspheres arepresent in the composition at a level of up to 30, 25, or 20 percent byweight, based on the total weight of the composition. For example, thehollow glass microspheres may be present in the composition in a rangefrom 5 to 30, 10 to 25, or 10 to 20 percent by weight, based on thetotal weight of the composition.

While in the compositions according to the present disclosure, whichinclude impact modifier, compatibilizer, and hollow glass microspheresas described above in any of their embodiments, the presence of each ofthese is critical to the performance of the final composition. As shownthroughout the examples, below, while the addition of an impact modifiercan improve the impact strength of a composition including a polyolefinand hollow glass microspheres, it typically does so at the expense oftensile strength and flexural strength. The addition of a compatibilizerto these compositions typically significantly enhances the tensilestrength, flexural strength, and impact strength. As shown in Table 10,the presence of compatibilizers does not significantly change the impactstrength of polypropylene containing hollow glass microspheres in theabsence of an impact modifier. Surprisingly, the improvement in impactstrength when a compatibilizer is used in the presence of an impactmodifier does not occur in the absence of hollow glass microspheres.

The composition according to the present disclosure and/or useful forpracticing the method disclosed herein, which includes the polyolefincomprising first repeating units, the hollow glass microspheres, thepolyolefin impact modifier, and the compatibilizer as described above inany of their embodiments has a melt flow index that renders it suitablefor injection molding. Typically, the composition has a melt flow indexat 190° C. and 2.16 kilograms of at least 3 grams per 10 minutes (insome embodiments, at least 5, 10, 15, 20, 25, 30, 35, 40, or 50 gramsper 10 minutes). In some embodiments, the composition has a melt flowindex at 190° C. and 2.16 kilograms of at least 3.5 grams per 10 minutes(in some embodiments, at least 4, 4.5, or 50 grams per 10 minutes). Themelt flow index of the polyolefin is measured by ASTM D1238-13: StandardTest Method for Melt Flow Rates of Thermoplastics by ExtrusionPlastometer.

In some embodiments of the composition according to the presentdisclosure, the hollow glass microspheres may be treated with a couplingagent to enhance the interaction between the hollow glass microspheresand the polyolefin matrix. In other embodiments, a coupling agent can beadded directly to the composition. Examples of useful coupling agentsinclude zirconates, silanes, or titanates. Typical titanate andzirconate coupling agents are known to those skilled in the art and adetailed overview of the uses and selection criteria for these materialscan be found in Monte, S. J., Kenrich Petrochemicals, Inc., “Ken-React®Reference Manual—Titanate, Zirconate and Aluminate Coupling Agents”,Third Revised Edition, March, 1995. If used, coupling agents arecommonly included in an amount of about 1% to 3% by weight, based on thetotal weight of the hollow glass microspheres in the composition.

Suitable silanes are coupled to glass surfaces through condensationreactions to form siloxane linkages with the siliceous glass. Thistreatment renders the filler more wet-able or promotes the adhesion ofmaterials to the hollow glass microsphere surface. This provides amechanism to bring about covalent, ionic or dipole bonding betweenhollow glass microspheres and organic matrices. Silane coupling agentsare chosen based on the particular functionality desired. Anotherapproach to achieving intimate hollow glass microsphere-polymerinteractions is to functionalize the surface of microsphere with asuitable coupling agent that contains a polymerizable moiety, thusincorporating the material directly into the polymer backbone. Examplesof polymerizable moieties are materials that contain olefinicfunctionality such as styrenic, vinyl (e.g., vinyltriethoxysilane,vinyltri(2-methoxyethoxy) silane), acrylic and methacrylic moieties(e.g., 3-metacrylroxypropyltrimethoxysilane). Examples of useful silanesthat may participate in vulcanization crosslinking include3-mercaptopropyltrimethoxysilane, bis(triethoxysilipropyl)tetrasulfane(e.g., available under the trade designation “SI-69” from EvonikIndustries, Wesseling, Germany), and thiocyanatopropyltriethoxysilane.Still other useful silane coupling agents may have amino functionalgroups (e.g., N-2-(aminoethyl)-3-aminopropyltrimethoxysilane and(3-aminopropyl)trimethoxysilane). Coupling agents useful forperoxide-cured rubber compositions typically include vinyl silanes.Coupling agents useful for sulfur-cured rubber compositions typicallyinclude mercapto or polysulfido silanes. Suitable silane couplingstrategies are outlined in Silane Coupling Agents: Connecting AcrossBoundaries, by Barry Arkles, pg 165-189, Gelest Catalog 3000—A Silanesand Silicones: Gelest Inc. Morrisville, Pa.

Although coupling agents are useful in some embodiments, advantageously,the compositions according to the present disclosure provide goodmechanical properties even in the absence of coupling agents. Themechanical properties achieved may be understood by a person skilled inthe art to be due to good adhesion between the hollow glass microspheresand the polyolefin matrix. Accordingly, in some embodiments, the hollowglass microspheres in the compositions according to the presentdisclosure are not treated with a silane coupling agent. Further, insome embodiments, compositions according to the present disclosure aresubstantially free of a silane coupling agent. Compositionssubstantially free of silane coupling agents may be free of silanecoupling agents or may have silane coupling agents present at a level ofless than 0.05, 0.01, 0.005, or 0.001 percent by weight, based on thetotal weight of the composition.

In some embodiments, the compositions according to and/or useful in themethod according to the present disclosure includes one or morestabilizers (e.g., antioxidants or hindered amine light stabilizers(HALS)). For example, any of the compositions, masterbatch compositions,or the let-down compositions described herein can include one or more ofsuch stabilizers. Examples of useful antioxidants include hinderedphenol-based compounds and phosphoric acid ester-based compounds (e.g.,those available from BASF, Florham Park, N.J., under the tradedesignations “IRGANOX” and “IRGAFOS” such as “IRGANOX 1076” and “IRGAFOS168”, those available from Songwon Ind. Co, Ulsan, Korea, under thetrade designations “SONGNOX”, and butylated hydroxytoluene (BHT)).Antioxidants, when used, can be present in an amount from about 0.001 to1 percent by weight based on the total weight of the composition. HALSare typically compounds that can scavenge free-radicals, which canresult from photodegradation or other degradation processes. SuitableHALS include decanedioic acid, bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl)ester. Suitable HALSinclude those available, for example, from BASF under the tradedesignations “TINUVIN” and “CHIMASSORB”. Such compounds, when used, canbe present in an amount from about 0.001 to 1 percent by weight based onthe total weight of the composition.

Reinforcing filler may be useful in the composition according to and/oruseful in the method according to the present disclosure. For example,any of the compositions, masterbatch compositions, or the let-downcompositions described herein can include one or more of suchreinforcing fillers. Reinforcing filler can be useful, for example, forenhancing the tensile, flexural, and/or impact strength of thecomposition. Examples of useful reinforcing fillers include silica(including nanosilica), other metal oxides, metal hydroxides, and carbonblack. Other useful fillers include glass fiber, wollastonite, talc,calcium carbonate, titanium dioxide (including nano-titanium dioxide),wood flour, other natural fillers and fibers (e.g., walnut shells, hemp,and corn silks), and clay (including nano-clay).

However, in some embodiments, the presence of silica in the compositionaccording to the present disclosure can lead to an undesirable increasein the density of the composition. Advantageously, the compositionsaccording to the present disclosure and/or useful in the methodsaccording to the present disclosure provide good mechanical propertieseven in the absence of reinforcing fillers. As shown in the Examples,below, it has been found that compositions disclosed herein have hightensile, flexural, and impact strength even in the absence of silicafiller or other reinforcing filler. Accordingly, in some embodiments,the composition is free of reinforcing filler or contains up to 5, 4, 3,2, or 1 percent by weight reinforcing filler, based on the total weightof the composition. For example, in some embodiments, the composition isfree of talc or contains up to 5, 4, 3, 2, or 1 percent by weight talc,based on the total weight of the composition. In some embodiments, thecomposition contains less than 5 percent by weight talc, based on thetotal weight of the composition. In another example, the compositionaccording to the present disclosure is free of or comprises less thanone percent by weight of montmorillonite clay having a chip thickness ofless than 25 nanometers. In another example, the composition accordingto the present disclosure is free of or comprises or comprises less thanone percent by weight of calcium carbonate having a mean particle sizeof less than 100 nanometers.

Other additives may be incorporated into the composition disclosedherein in any of the embodiments described above. Examples of otheradditives that may be useful, depending on the intended use of thecomposition, include preservatives, mixing agents, colorants,dispersants, floating or anti-setting agents, flow or processing agents,wetting agents, anti-ozonant, and odor scavengers. Any of thecompositions, masterbatch compositions, or the let-down compositionsdescribed herein can include one or more of such additives.

Compositions according to the present disclosure are suitable forinjection molding. Elevated temperatures (e.g., in a range from 100° C.to 225° C.) may be useful for mixing the components of the compositionin an extruder. Hollow glass microspheres may be added to thecomposition after the polyolefin, compatilizer, and impact modifier arecombined. The method of injection molding the composition disclosedherein can utilize any type of injection molding equipment, generallyincluding a material hopper (e.g., barrel), a plunger (e.g., injectionram or screw-type), and a heating unit.

The composition and method according to the present disclosure areuseful for making low density products (e.g., having a density in arange from 0.75 to 0.95, 0.78 to 0.9, or 0.8 to 0.9 grams per cubiccentimeter) with good tensile strength, flexural strength, and impactresistance, which are useful properties for a variety of applications.Articles that can be made by injecting molding the compositionsaccording to the present disclosure include hardhats and interior andexterior automobile component (e.g., hoods, trunks, bumpers, grilles,side claddings, rocker panels, fenders, tail-gates, in wire and cableapplications, instrument panels, consoles, interior trim, door panels,heater housings, battery supports, headlight housings, front ends,ventilator wheels, reservoirs, and soft pads).

In many embodiments, as shown in the Examples, below, at least one ofthe impact strength, tensile strength, or flexural strength of thecompositions according to the present disclosure approach or in somecases even surprisingly exceed the impact strength of the polyolefinwithout the addition of hollow glass microspheres.

Some Embodiments of the Disclosure

In a first embodiment, the present disclosure provides a compositioncomprising:

a polyolefin comprising first repeating units;

hollow glass microspheres;

a polyolefin impact modifier that is chemically non-crosslinked and freeof polar functional groups; and

a compatibilizer comprising the first repeating units and secondrepeating units, which are the first repeating units modified with polarfunctional groups,

wherein the hollow glass microspheres are present in a range from 40% to70% by volume, the polyolefin impact modifier is present in a range from20% to 50% by volume, and the compatibilizer is present in a range from4% to 12% by volume, based on the total volume of the hollow glassmicrospheres, the polyolefin impact modifier, and the compatibilizer.The composition may also have any of the following features, alone or incombination:

the composition comprises greater at least ten percent by weight of theglass, based on the total weight of the composition;

the polyolefin is other than a polypropylene homopolymer;

the composition has a melt flow index at 190° C. and 2.16 kilograms ofat least 3 grams per 10 minutes;

the composition has a notched izod impact strength of at least 60joules/meter,

the polyolefin comprises polyethylene, and the compatibilizer comprisesethylene repeating units;

the first repeating units are polypropylene repeating units, and thecompatibilizer comprises propylene repeating units, and the polyolefinis a copolymer comprising at least 80% by weight propylene unit or thepolyolefin is a medium or high impact polypropylene.

In an alternate first embodiment, the present disclosure provides amasterbatch composition for combining with a polyolefin comprising firstrepeating units, wherein the masterbatch comprises:

hollow glass microspheres;

a polyolefin impact modifier that is chemically non-crosslinked and freeof polar functional groups; and

a compatibilizer comprising the first repeating units and secondrepeating units, which are the first repeating units modified with polarfunctional groups,

wherein the hollow glass microspheres are present in a range from 40% to65% by volume, the polyolefin impact modifier is present in a range from20% to 50% by volume, and the compatibilizer is present in a range from4% to 15% by volume, based on the total volume of the hollow glassmicrospheres, the polyolefin impact modifier, and the compatibilizer.

In a second embodiment, the present disclosure provides the compositionof the first embodiment, wherein the polyolefin comprises at least oneof polyethylene or polypropylene.

In a third embodiment, the present disclosure provides the compositionof the first or second embodiment, wherein the first repeating units arepolyethylene repeating units.

In a fourth embodiment, the present disclosure provides the compositionof any one of the first to third embodiments, wherein the polyolefinimpact modifier has a melt flow index at 190° C. and 2.16 kilograms ofat least 10 grams per 10 minutes.

In a fifth embodiment, the present disclosure provides the compositionof any one of the first to fourth embodiments, comprising greater thanten percent by weight of the hollow glass microspheres, based on thetotal weight of the composition.

In a sixth embodiment, the present disclosure provides the compositionof any one of the first to fifth embodiments, comprising greater thantwo percent by weight of the compatibilizer, based on the total weightof the composition.

In a seventh embodiment, the present disclosure provides the compositionof any one of the first to sixth embodiments, comprising greater thanthree percent by weight of the compatibilizer, based on the total weightof the composition.

In an eighth embodiment, the present disclosure provides the compositionof any one of the first to seventh embodiments, wherein thecompatibilizer is a maleic anhydride-modified polyolefin.

In a ninth embodiment, the present disclosure provides the compositionof any one of the first to eighth embodiments, further comprisingreinforcing fillers.

In a tenth embodiment, the present disclosure provides the compositionany one of the first to ninth embodiments, wherein the compositioncomprises less than five percent by weight talc, based on the totalweight of the composition.

In an eleventh embodiment, the present disclosure provides thecomposition of any one of the first to tenth embodiments, wherein thecomposition comprises less than one percent by weight of at least one ofmontmorillonite clay having a chip thickness of less than 25 nanometersor calcium carbonate having a mean particle size of less than 100nanometers.

In a twelfth embodiment, the present disclosure provides the compositionof any one of the first to eleventh embodiments, wherein the hollowglass microspheres are not treated with a silane coupling agent.

In a thirteenth embodiment, the present disclosure provides thecomposition of any one of the first to twelfth embodiments, wherein ahydrostatic pressure at which ten percent by volume of the hollow glassmicrospheres collapses is at least about 50 megapascals.

In a fourteenth embodiment, the present disclosure provides thecomposition of any one of the first to thirteenth embodiments, whereinthe polyolefin impact modifier is an ethylene propylene elastomer, anethylene octene elastomer, an ethylene propylene diene elastomer, anethylene propylene octene elastomer, or a combination thereof.

In a fifteenth embodiment, the present disclosure provides thecomposition of any one of the first to fourteenth embodiments, whereinthe polyolefin impact modifier is an ethylene octene elastomer.

In a sixteenth embodiment, the present disclosure provides an articlecomprising a solidified composition of any one of the first to fifteenthembodiments.

In a seventeenth embodiment, the present disclosure provides the articleof the sixteenth embodiment, wherein the article is a hardhat.

In an eighteenth embodiment, the present disclosure provides the articleof the sixteenth embodiment, wherein the article is an interior orexterior automobile component.

In a nineteenth embodiment, the present disclosure provides a method ofmaking an article, the method comprising injection molding thecomposition of any one of the first to fifteenth embodiments to make thearticle.

In a twentieth embodiment, the present disclosure provides the method ofthe nineteenth embodiment, wherein the article is a hardhat.

In a twenty-first embodiment, the present disclosure provides the methodof the nineteenth embodiment, wherein the article is an interior orexterior automobile component.

The following specific, but non-limiting, examples will serve toillustrate the invention. In these examples, all amounts are expressedin parts per hundred resin (phr) unless specified otherwise. In theseexamples, N/M means “not measured”.

EXAMPLES Materials

TABLE 1 Abbreviation Material Description PP1 Commercially availablefrom LyondellBasell, Houston, TX, under the trade designation “PRO-FAX6523”. Low impact polypropylene homopolymer. Melt flow rate (MFI) 4.00g/10 min (230° C./2.16 kg) PP2 Commercially available fromLyondellBasell, Houston, TX, under the trade designation “PRO-FAX 7523”.Medium impact polypropylene copolymer. Melt flow rate 4.00 g/10 min(230° C./2.16 kg) PP3 Commercially available from LyondellBasell,Houston, TX, under the trade designation “PRO-FAX 8523”. Very highImpact polypropylene copolymer. Melt flow rate 4.00 g/10 min (230°C./2.16 kg) PP4 Commercially available from Pinnacle Polymers,Garyville, LA, under the trade designation “Pinnacle PP 4208”. HighImpact PP copolymer. Melt Flow rate 8.00 g/10 min (230° C./2.16 kg) PP5Commercially available from Pinnacle Polymers, Garyville, LA, under thetrade designation “Pinnacle PP 4220H”. High Impact PP copolymer. MeltFlow rate 20.00 g/10 min (230° C./2.16 kg) PP6 Commercially availablefrom Pinnacle Polymers, Garyville, LA, under the trade designation“Pinnacle PP 4130H”. High Impact PP copolymer. Melt flow rate 35.00 g/10min (230° C./2.16 kg) PP7 Commercially available from Pinnacle Polymers,Garyville, LA, under the trade designation “Pinnacle PP 4150H”. HighImpact PP copolymer. Melt Flow rate 55.00 g/10 min (230° C./2.16 kg) PP8Commercially available from LyondellBasell, Houston, TX, under the tradedesignation “Hifax CA 387 A”. It is a reactor TPO (thermoplasticpolyolefin) manufactured using LyondellBasell's Catalloy processtechnology. Melt flow rate (MFI) 18.00 g/10 min (230° C./2.16 kg) C1Maleic anhydride modified homopolymer polypropylene under the trade namePOLYBOND ® 3200 available from Addivant. Melt flow rate (190 C./2.16 kg)115 g/10 min. 0.8-1.2% Maleic anhydride content, C2 Maleic anhydridemodified high density polyethylene under the trade name POLYBOND ® 3009available from Addivant. Melt flow rate (190 C./2.16 kg) 3-6 g/10 min.0.8-1.2% Maleic anhydride content, C3 An anhydride modified polyethylenecommercially available from E. I. du Pont de Nemours and Company(Wilmington, DE) under the trade designation Fusabond ® E226. IM1Polyolefin elastomer (ethylene octene copolymer) with a nominal loosetalc coating, commercially available under the trade designationEngage ® 8407 with a melt flow rate (190 C./2.16 kg) 13 g/10 min fromDow Chemical Company (Midland, MI) IM2 Polyolefin elastomer (ethyleneoctene copolymer) with a nominal loose talc coating, commerciallyavailable under the trade designation Engage ® 8137 with a melt flowrate (190 C./2.16 kg) 13 g/10 min from Dow Chemical Company (Midland,MI) IM3 Polyolefin elastomer (ethylene octene copolymer) commerciallyavailable under the trade designation Engage ® 8100 with a melt flowrate (190 C./2.16 kg) 1 g/10 min from Dow Chemical Company (Midland MI)IM4 Commercially available from LyondellBasell, Houston, TX, under thetrade designation “Hifax CA 138 A”. It is a reactor TPO (thermoplasticpolyolefin) manufactured using LyondellBasell's Catalloy processtechnology. Melt flow rate (MFI) 2.8 g/10 min (230° C./2.16 kg) GB1 3M ™iM16K Hi-Strength Glass Bubbles with 16,000 psi crush strength, 20micron average diameter and 0.46 g/cc true density commerciallyavailable from 3M Company, St. Paul, MN under the trade designation “3MiM16K Hi-Strength Glass Babbles” GB2 Hollow glass microspherescommercially available from Sinosteel Maanshan Inst. of Mining ResearchCo. ltd. under the trade designation “Y8000” (8600 psi crush strength at80% survival and 0.6 g/cc true density as measured by 3M using ASTM TestMethod D3102-78 (1982); “DETERMINATION OF ISOSTATIC COLLAPSE STRENGTH OFHOLLOW GLASS MICROSPHERES” with exceptions. The sample size of hollowmicrospheres was 10 true cc. The hollow microspheres were dispersed inglycerol (20.6 g), and data reduction was automated using computersoftware. The 80% crush strength value reported herein is the isostaticpressure at which 20 percent by volume of the glass microbubblescollapse.) HDPE A high-density polyethylene (hard hat grade) forinjection molding with melt flow rate (190 C./2.16 kg) 5 g/10 min,commercially available from BRASKEM S.A. (Sao Paolo, Brazil) under thetrade designation “IE59U3”

Test Methods Density

Density of the molded parts was determined using the followingprocedure. First, the molded parts were exposed to high temperature in aoven (Nabertherm® N300/14) in order to volatilize the polymer resin. Theoven was set with a temperature ramp profile to run from 200° C. to 550°C. in 5 hours. After the temperature reached 550° C., it was keptconstant for 12 hours. Weight percent of glass bubbles was calculatedfrom the known amounts of molded part before and after the burn processusing the following equation:

Weight % of Glass Bubbles=(Weight of Residual Inorganics AfterBurn)/(Weight of Molded Material Before Burn)×100

We then determine the density of the glass bubble residue (d_(GB)) usinga helium gas pycnometer (AccuPcy 1330 from Micromeritics). Finally, themolded part density is calculated from the known weight percent of glassbubble residue (W % GB), weight percent of polymer phase (1−w % GB), thedensity of glass bubble residue (d_(GB)) and the known polymer density(d_(polymer)) from supplier datasheet.

$\rho_{{molded}\mspace{11mu} {part}} = \frac{1}{\frac{W\mspace{14mu} \%_{GB}}{d_{GB}} + \frac{W\mspace{14mu} \%_{polymer}}{d_{polymer}}}$

Mechanical Properties

Mechanical properties of the injection-molded composites were measuredusing ASTM standard test methods listed in Table 2. An MTS frame with a5 kN load cell and tensile and 3 point bending grips were used fortensile and flexural properties, respectively. In tensile testing mode,the test procedure described in ASTM D-638-10 standard was followed,however no strain gauge was used, and instead, grip separation distancewas used to determine the sample elongation. Tinius Olsen model 1T503impact tester and its specimen notcher were used to measure roomtemperature Notched Izod impact strength of the molded parts. A TiniusOlsen MP200 extrusion plastometer was used for melt flow index testingon samples. At least 5 different specimens from a given sample weretested in all tensile, flexural, and impact tests. Arithmetic average ofthe results were determined and reported in the following examples. Theresults were observed to be highly repeatable and the standard deviationin test results was observed to be in the range of 3-5% or lower. Atleast two different specimens were tested in melt flow index tests. Themelt flow tests were observed to be highly repeatable with almostidentical experimental results. Arithmetic average of the results weredetermined and reported in the following examples.

TABLE 2 Property Test Methods Test (Unit) Abbr. ASTM # Tensile Modulus(MPa) @ °20 C. TM D-638-10 Tensile Strength at yield (MPa) °20 C. TSD-638-10 Elongation at break (%) EL D-638-10 Notched Izod Impact @ °20C. (J/m) NI D-256-10 Flexural Modulus (MPa) FM D-790-10 FlexuralStrength at yield (MPa) FS D-790-10 Melt Flow Index MFI D-1238-13

Compounding Procedure

Samples were compounded in a co-rotating intermeshing 1 inch twin screwextruder (L/D: 25) equipped with 7 heating zones. Polymer pellets(polypropylene or HDPE), the impact modifier and compatibilizers weredry blended and fed in zone 1 via a resin feeder and then passed througha set of kneading blocks and conveying elements. The extrudate wascooled in a water bath and pelletized. The pelletized blend was thenreintroduced through the resin feed hopper and passed through thekneading block section again to ensure its complete melting before glassbubbles were side fed downstream in zone 4. At the point of glass bubbleside feeding as well as for the rest of the downstream processing, highchannel depth conveying elements (OD/ID: 1.75) were used.

For polypropylene, the temperature in zone 1 was set to 150° C. and allother zones to 220° C. For HDPE, zone 1 was set to 150° C. and allothers were set to 215° C. respectively. The screw rotation speed wasset to 250 rpm in both cases. The extrudate was cooled in a water bathand pelletized.

Injection Molding Procedure

All samples were molded using a BOY22D injection molding machine with a28 mm general purpose barrel and screw manufactured by Boy MachinesInc., Exton, Pa. A standard ASTM mold with cavities for tensile, flexand impact bar was used for all molded parts. The injection moldedspecimens were kept on a lab bench at room temperature and under ambientconditions for at least 36 hours before performing any testing.

Comparative Examples 1A-1C and Example 1 High Density Polyethylene BasedFormulations

The addition of 12 wt % GB1 (0.46 g/cc) to HDPE reduces density by about10% (compare CE1A and CE1B) but the reduction in density comes at theexpense of 65% decrease in notched impact strength. The tensile strengthalso is reduced because there is less resin to withstand the appliedforces causing yielding at lower stress levels. The benefits, on theother hand, are increased stiffness as evidenced by increased level oftensile and flex modulus.

In order to compensate for the decreased impact strength, a lowviscosity Impact modifier 1 (MFI 30 g/10 min @190 C/2.16 kg) is added inCE1C. The addition of this impact modifier increases notched impactstrength from 32 J/m to 37 J/m, which is still well below that ofunfilled HDPE (91 J/m). The increase in impact strength comes at theexpense of decreased tensile strength (from 23.3 MPa to 18 MPa due toglass bubbles and further to 14.2 MPa due to the addition of the impactmodifier) and flexural strength (from 24.9 to 20.0 MPa).

When a functional compatibilizer based on polyethylene such as C2 isused along with the impact modifier, the notched impact strength furtherincreases remarkably from 37 J/m to 120 J/m while also increasingtensile and flexural strength (CE1C and EX1).

TABLE 3 HDPE Based Formulas CE1C EX1 HDPE with glass HDPE with glassCE1B bubbles bubbles, impact CE1A HDPE with and impact modifier and HDPEglass bubbles modifier compatibilizer Wt % Vol % Wt % Vol % Wt % Vol %Wt % Vol % HDPE 100 100 88 19.3 70.5 62.5 66.2 58.7 GB1 — — 12.0 20.712.0 20.4 12.0 20.4 IM1 — — — — 17.5 17.1 17.7 17.2 C2 — — — — — — 4.13.7 Density 0.959 0.859 0.825 0.829 (g/cc) % Density — 10.4 14.0 13.6Reduction TS (Mpa) 23.2 18.0 14.2 20.0 TM (Mpa) 870 1415 900 875 EL (%)limit 115 200 16 FS (Mpa) 24.9 27.0 20.0 22.4 FM (Mpa) 694 872 610 570 @2% secant NI (J/m) 91 32 37 120 MFI (190° C., 7.5 4.2 4.8 4.5 2.16 kg)MFI/density 7.8 5.1 5.6 5.3 (1/g/cc)

Examples 2-4 Effect of Impact Modifier Viscosity and Blends in HDPE

Examples 2-4 in Table 3 show that the use of a higher MFI impactmodifier such as IM1 (MFI=30) in EX1 results in a higher composite finalMFI whereas a lower MFI impact modifier such as IM3 (MFI=1) in EX2results in a lower composite final MFI.

The use of higher MFI impact modifiers in EX1 and EX3 do not affectadversely the final MFI of the composite while the lower MFI impactmodifier in EX2 may adversely affect the final composite MFI. EX4 showsthat one can blend a high and low MFI impact modifier for an optimizedviscosity. Hence, this invention also includes those impact modifierswhich are blends of high and low MFI impact modifiers.

Correct Selection of Compatibilizer

Table 4 demonstrates that the correct selection of C2 for HDPE (EX3)improves the impact strength vs. selecting C1 for HDPE (CE1B). Thecompatibilizer is chosen such that the back bone where the functionalgrafts are attached can co-crystallize and compatible with the mainmatrix resin.

TABLE 4 HDPE Based Formulas CE1A EX1 EX2 EX3 CE1B CE1C EX4 Wt % Vol % Wt% Vol % Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol % HDPE 100100 66.2 58.7 66.2 58.7 66.2 58.7 66.2 58.7 70.5 62.5 66.2  58.7  GB1 —— 12.0 20.4 12.0 20.4 12.0 20.4 12.0 20.4 12.0 20.4 12.0  20.4  IM1 — —17.7 17.2 — — — — — — — — 8.8 8.6 IM2 — — — — — — 17.7 17.2 17.7 17.217.5 17.1 — — IM 3 — — — — 17.7 17.2 — — — — — — 8.9 8.6 C2 — —  4.1 3.7  4.1  3.7  4.1  3.7 — — — — 4.1 3.7 C1 — — — — — — — —  4.1  3.7 —— — — Density (g/cc) 0.959 0.829 0.857 0.852 0.834 0.851 0.846 %Reduction — 13.6 10.6 11.2 13.0 11.2 11.8 TS (Mpa) 23.2 20.0 18.0 18.013.0 13.1 18.3 TM (Mpa) 870 875 800 858 700 765 870 EL (%) limit 16 3640 Limit Limit 34 FS (Mpa) 24.9 22.4 20.0 19.7 16.8 18.0 20.1 FM (Mpa) @2% 694 570 560 562 487 570 575 secant NI (J/m) 91 120 362 275 43 65 227MFI (190 C. 7.5 4.5 2.6 4.3 3.5 4.5 3.6 2.16 kg) MFI/density 7.8 5.4 3.05.0 4.2 5.4 4.3 (1/g/cc)

Example 5 and Comparative Examples 2A-2C Low Impact PolypropyleneHomopolymer Based Formulations

As seen in Table 4, similar to that seen with HDPE, the addition ofglass bubbles to polypropylene homopolymer reduces density by about 9.3%(compare CE2A and CE2B) but the reduction in density comes at theexpense of about a 50% decrease in notched impact strength.

In order to compensate for the decreased impact strength, a lowviscosity impact modifier Impact modifier 1 (MFI 30 g/10 min @190 C/2.16kg) is added in CE2C. The addition of this impact modifier increases thenotched impact strength 87% from 24.7 to 46.3 J/m. The increase inimpact strength comes at the expense of decreased tensile strength (from29.2 MPa to 19.3 MPa due to glass bubbles and further down to 13.9 MPadue to the addition of the impact modifier) and flexural strength (from37.6 to 23.8 MPa).

When a functional compatibilizer based on polypropylene (C1) is usedalong with the impact modifier, the notched impact strength further isfurther increased from 46.3 J/m to 60 Jim while also increasing tensileand flexural strength (compare 3 and 4).

TABLE 5 Low Impact Polypropylene Homopolymer Based Formulations CE2ACE2B CE2C EX5 Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol % PP1 100 100 9078 69 62 65 58.3 GB1 — — 14 22 14 22 14 22.0 C1 — — — — — — 4 3.6 IM1 —— — — 17 16 17 16.1 Density (g/cc) 0.9 0.816 0.802 0.801 TS(Mpa) 29.219.3 13.9 19.1 TM (Mpa) 1190 1690 900 1180 EL (Mpa) limit 140 limit 14FS (Mpa) 37.6 34.5 23.8 28.9 FM (Mpa) @ 1063 1575 970 1075 1% secant NI(J/m) 48 24.7 46.3 60.0 MFI (210° C. 4.7 2.3 3.8 4.7 2.16 kg)MFI/density 5.2 2.8 4.7 5.9 (1/g/cc)

Examples 6-8 Effect of Impact Modifier Viscosity and Blends in LowImpact Polypropylene

As seen in Table 5 the use of a higher MFI impact modifier such as IM1(MFI=30) in EX5 results in a final composite MFI of 5.5 whereas a lowerMFI impact modifier such as IM3 (EX7) results in a final composite MFIof 2.9.

The use of higher MFI impact modifiers EX5 and EX63 do not affectadversely the final MFI of the composite. EX8 shows that one can blend ahigh and low MFI impact modifier for an optimized viscosity.

TABLE 6 Low Impact Polypropylene Homopolymer Based Formulations CE2A EX5EX6 EX7 EX8 Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol % PP1100 100 65 58.3 65 58.3 65 58.3 65 58.3 GB1 — — 14 22.0 14 22.0 14 22.014 22.0 C1 — —  4  3.6  4  3.6  4  3.6  4 3.6 IM1 — — 17 16.1 — — — —  8.5 8.05 IM2 — — — — 17 16.1 — — — — IM3 — — — — — — 17 16.1   8.58.05 Density (g/cc) 0.9 0.801 0.797 0.798 0.798 TS (Mpa) 29.2 19.1 20.822.0 21.9 TM (Mpa) 1190 1180 1170 1228 1207 EL (MPa) limit 14 26 25 29FS (Mpa) 37.6 28.9 29.4 31.4 30.3 FM (Mpa) @ 1063 1075 1030 1090 1050 1%secant NI (J/m) 48 60.0 87 125 85 MFI (210° C. 4.7 5.5 4.4 2.9 3.9 2.16kg) MFI/density 5.2 6.9 5.5 3.6 4.9 (1/g/cc)

Example 9 and Comparative Examples 3A-3C Medium Impact PolypropyleneCopolymer Based Formulations

In example 9, we demonstrate that the same effect is observed in amedium impact polypropylene as in a low impact polypropylene (increasingimpact strength while increasing tensile and flex strength.

The addition of glass bubbles reduces density by about 9.3% (compareCE3A and CE3B) but the reduction in density comes at the expense ofabout a 55% decrease in notched impact strength.

In order to compensate for the decreased impact strength, a lowviscosity impact modifier IM1 (MFR 30 g/10 min @190° C./2.16 kg) isadded in CE3C. The addition of this impact modifier increases thenotched impact strength 146% from 37.6 to 92.7 J/m. The increase inimpact strength comes at the expense of decreased tensile strength (from26.6 MPa to 16.5 MPa due to glass bubbles and further down to 12.7 MPadue to the addition of the impact modifier) and flexural strength (from34.6 to 29.3 MPa).

When a functional compatibilizer is used along with the impact modifier,the notched impact strength further is further increased from 92.7 J/mto 122 J/m while also increasing tensile and flexural strength (compareformula CE3C and Ex9).

TABLE 7 Medium Impact Polypropylene Copolymer Based Formulations CE3ACE3B CE3C EX9 Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol % PP2 100 100 9078 69 62 65 58.3 GB1 — — 14 22 14 22 14 22.0 C1 — — — — — — 4 3.6 IM1 —— — — 17 16 17 16.1 Density (g/cc) 0.9 0.803 0.799 0.797 TS (Mpa) 26.616.5 12.7 16.6 TM (Mpa) 1083 1390 830 1031 EL (Mpa) limit limit limit25.6 FS (Mpa) 34.5 29.3 19.8 24.9 FM (Mpa) @ 1% 1151 1405 885 1006secant NI (J/m) 84.1 37.6 92.7 122.0 MFI (210° C. 4 2.55 2.75 3.8 2.16kg) MFI/density 4.5 3.2 3.4 4.8 (1/g/cc)

Example 10 and Comparative Examples CE4A-4C High Impact PolypropyleneCopolymer Based Formulations

Several automobile plastics use high impact polypropylenes (especiallyin exteriors) and weight reduction with glass bubbles has had a hardertime penetrating into parts that require high impact. In example 10, wedemonstrate that this invention is also applicable in high impactpolymers and could help meet specifications that require high impact.Note that we are using 14 wt % GB1 alone and that reinforcing fillerssuch as talc and glass fibers can easily be added to reinforce thesecurrent formulas and increase modulus and strength further.

In high impact polypropylene, the notched impact strength reduction issignificant at 87% from 545 J/m to 65 J/m. We are significantlyrecovering impact strength up to 215 J/m with no detriment on density.In example 10, we demonstrate that the combined low viscositynon-functionalized impact modifier and functional compatibilizer alsoshows the same improvement of increasing impact strength whileincreasing tensile and flex strength.

TABLE 8 High Impact Polypropylene Copolymer Based Formulations CE4A CE4BCE4C EX 10 Vol Vol Vol Vol Wt % % Wt % % Wt % % Wt % % PP3 100 100 90 7869 62 65 58.3 GB1 — — 14 22 14 22 14 22.0 C1 — — — — — — 4 3.6 IM1 — — —— — — 17 16.1 Density (g/cc) 0.89 0.803 0.806 0.800 TS (Mpa) 20.6 13.111.5 14.0 TM (Mpa) 823 1307 748 851 EL (Mpa) limit 70 limit 45 FS (Mpa)27.2 23.6 15.8 20.4 FM (Mpa) @ 912 1240 792 820 1% secant NI (J/m) 54566 180 215 MFI (210° C. 4 2.35 2.2 3.25 2.16 kg) MFI/density 4.5 2.9 2.74.1 (1/g/cc)

Example 11 and Comparative Examples 5A-5D Effect of Impact ModifierViscosity and Blends in High Impact Polypropylene

TABLE 9 High Impact Polypropylene Homopolymer Based Formulations CE5ACE5B CE5C CE5D EX 11 Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol % Wt %Vol % PP3 100 100 65 58.3 65 58.3 65 58.3 65 58.3 GB1 — — 14 22.0 1422.0 14 22.0 14 22.0 C1 — — 4 3.6 4 3.6 4 3.6 4 3.6 IM1 — — 17 16.1 — —— — 8.5 8.05 IM2 — — — — 17 16.1 — — — — IM3 — — — — — — 17 16.1 8.58.05 Density 0.89 0.800 0.792 0.792 0.793 (g/cc) TS (Mpa) 20.6 14.0 14.215.0 14.8 TM (Mpa) 823 850 875 900 880 EL (Mpa) limit 45 59 60 64 FS(Mpa) 27.2 20.4 20.0 20.9 20.4 FM (Mpa) 912 820 1030 1090 1050 @ 1%secant NI (J/m) 545 215 275 318 295 MFI (210° C. 4 3.3 3.1 2.4 2.6 2.16kg) MFI/density 4.5 4.1 3.9 3.0 3.3 (1/g/cc)

Comparative Examples 6A-6F Compatibilizer Only

Using Compatibilizer Alone without Impact Modifier

Table 10, the presence of compatibilizers does not significantly changenotched impact strength significantly neither in low, medium, or highimpact polymers.

TABLE 10 Effect of using Compatibilizer only without the Impact ModifierCE6A CE6B CE6C CE6D CE6E CE6F Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol% Wt % Vol % Wt % Vol % PP1 90 78 81 73.5 PP2 90 78 81 73.5 PP3 90 78 8173.5 GB1 14 22 14 22 14 22 14 22 14 22 14 22 C1 — — 5 4.5 — — 5 4.5 — —5 4.5 Density 0.816 0.795 0.803 0.795 0.803 0.800 (g/cc) TS (Mpa) 19.330.0 16.5 24.5 13.1 19.5 TM (Mpa) 1690 1760 1390 1647 1307 1349 EL (Mpa)140 5 limit 4.8 70 14 FS (Mpa) 34.5 43.9 29.3 37.3 23.6 30.2 FM (Mpa)1575 1525 1405 1467 1240 1365 @ 1% secant NI (J/m) 24.7 33.4 37.6 47.166.2 64.1 MFI 2.3 2.6 2.55 3.0 2.35 3.15 (210° C. 2.16 kg) MFI/density2.8 3.3 3.2 3.8 2.9 3.9 (1/g/cc)

Comparative Examples 7A-7F and Example 12 Correct Selection ofCompatibilizers

Table 11 demonstrates that the correct selection of C1 for PP1 (EX12)improves the impact strength vs. selecting C2 for PP1 (CE7E). Thecompatibilizer is chosen such that the back bone where the functionalgrafts are attached can co-crystallize and compatible with the mainmatrix resin.

TABLE 11 CE7A CE7B CE7C CE7D CE7E CE7F EX 12 Wt % Vol % Wt % Vol % Wt %Vol % Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol % PP1 100 100 90 78 6962 81 73.6 65 58.5 81 73.5 65 58.3 GB1 — — 14 22 14 22 14 22 14 22.0 1422 14 22.0 C1 — — — — — — — — — 5 4.5 4 3.6 C2 — — — — — — 5 4.4 4 3.5 —— — — IM1 — — — — 17 16 — — 17 16.0 — — 17 16.1 Density 0.9 0.816 0.8020.814 0.808 0.795 0.801 (g/cc) TS (Mpa) 29.2 19.3 13.9 25.1 16.1 30.019.1 TM (Mpa) 1190 1690 900 1650 930 1760 1180 EL (Mpa) limit 140 limit5 57 5 14 FS (Mpa) 37.6 34.5 23.8 40.2 26.1 43.9 28.9 FM (Mpa) 1063 1575970 1630 830 1525 1075 @ 1% secant NI (J/m) 48 24.7 46.3 23.8 44.7 33.460.0 MFI (210° C. 4.0 2.3 3.8 2.3 4.3 2.6 4.7 2.16 kg) MFI/density 4.42.8 4.7 2.8 5.3 3.3 5.9 (1/g/cc)

Example 13 and Comparative Examples 8A-8C Alternate Glass Bubble

Table 12 Formulations were similar to those in Table 3 except that analternate glass bubble was used. As Table 12 demonstrates the impactstrength of the composite is again improved with the combination of theimpact modifier and correct compatibilizer (EX13).

TABLE 12 CE8A CE8B CE8C EX 13 Vol Vol Vol Vol Wt % % Wt % % Wt % % Wt %% HDPE 100 100 88 20.7 72.5 70.0 66.2 63.7 GB2 — — 10 79.3 10.0 11.5 1213.8 IM — — — — 17.5 18.4 17.7 18.6 C2 — — — — — — 4.1 4.0 Density(g/cc) 0.959 0.939 0.926 0.923 % Reduction — 2 3.4 3.8 in Density TS(Mpa) 24.1 23.2 17.2 18.8 EL (%) 160 18 76 47 TM (Mpa) 973 1430 804 781FS (Mpa) 26.0 29.5 21.2 21.3 FM @ 2% 714 864 577 588 secant (Mpa) FM @1% 920 1133 732 740 secant (Mpa) NI (J/m) 91 39 71 112 MFI (190° C. 7.55.25 6.05 6.25 2.16 kg) MFI/density 7.8 5.6 6.5 6.8 (1/g/cc)

Examples 14, 15, 16 and Comparative Examples 9A-9C

TABLE 13 CE9A CE9B CE9C EX 14 EX 15 EX 16 Wt % Vol % Wt % Vol % Wt % Vol% Wt % Vol % Wt % Vol % Wt % Vol % PP4 100 100 90 78 69 62 65 58.3 6558.3 65 58.3 GB1 — — 14 22 14 22 14 22.0 14 22.0 14 22.0 C1 — — — — — —4 3.6 4 3.6 4 3.6 IM3 — — — — — — — — — — 17 16.1 IM2 — — — — — — — — 1716.1 — — IM1 — — — — 17 16 17 16.1 — — — — Density 0.90 0.814 0.8130.815 0.815 0.815 (g/cc) TS (Mpa) 21.6 13.0 10.6 15.2 15.0 15.6 TM (Mpa)906 1186 778 866 810 810 EL % Limit 134 Limit 60 80 80 Flexural 27.922.7 15.7 21.7 21.1 21.6 Strength (Mpa) FM @1% 915 1209 812 883 848 853Secant (Mpa) NI (J/m) 205 47 120 273 311 397 MFI 8.7 5.3 4.6 5.3 5.0 4.2(230° C. 2.16 kg) MFI/density 9.7 6.5 5.7 6.5 6.1 5.2 (1/g/cc)

Examples 17, 18, 19 and Comparative Examples 10A-10C

TABLE 14 CE10A CE10B CE10C EX 17 EX 18 EX 19 Wt % Vol % Wt % Vol % Wt %Vol % Wt % Vol % Wt % Vol % Wt % Vol % PP 5 100 100 90 78 69 62 65 58.365 58.3 65 58.3 GB1 — — 14 22 14 22 14 22.0 14 22.0 14 22.0 C1 — — — — —— 4 3.6 4 3.6 4 3.6 IM3 — — — — — — — — — — 17 16.1 IM2 — — — — — — — —17 16.1 — — IM1 — — — — 17 16 17 16.1 — — — — Density 0.90 0.814 0.8120.816 0.817 0.820 (g/cc) TS 21.5 12.3 9.7 14.0 13.8 14.3 (Mpa) TM 10511353 856 846 844 840 (Mpa) EL % Limit 40 138 45 42 36 FS 27.9 22.7 15.721.7 21.1 21.6 (Mpa) FM @ % 1056 1334 842 837 824 837 secant (Mpa) NI(J/m) 151 43 117 263 300 320 notched D256 MFI 20.6 10.7 10.2 10.3 9 6.8(230° C. 2.16 kg) MFI/density 22.9 13.1 12.6 12.6 11.0 8.3 (1/g/cc)

Examples 20, 21, 22 and Comparative Examples 11A-11C

TABLE 15 CE11A CE11B CE11C EX 20 EX 21 EX 22 Wt % Vol % Wt % Vol % Wt %Vol % Wt % Vol % Wt % Vol % Wt % Vol % PP 6 100 100 90 78 69 62 65 58.365 58.3 65 58.3 GB1 — — 14 22 14 22 14 22.0 14 22.0 14 22.0 C1 — — — — —— 4 3.6 4 3.6 4 3.6 IM3 — — — — — — — — — — 17 16.1 IM2 — — — — — — — —17 16.1 — — IM1 — — — — 17 16 17 16.1 — — — — Density (g/cc) 0.90 0.8100.813 0.815 0.817 0.815 TS (Mpa) 18.8 11.1 8.6 12.6 12.8 13.0 TM (Mpa)917 1245 802 782 780 776 EL % 51 20 70 23 28 18.5 FS (Mpa) 27.9 22.714.9 19.4 19.3 19.7 FM @ % 940 1205 790 810 800 800 secant (Mpa) NI(J/m) 168 46 126 200 265 276 notched D256 MFI (230° C. 36.6 18.1 14.714.7 13.4 10.2 2.16 kg) MFI/density 40.7 22.3 18.1 18.0 16.4 12.5(1/g/cc)

Examples 23, 24, 25 and Comparative Examples 12A-12C

TABLE 16 CE12A CE12B CE12C EX 23 EX 24 EX 25 Wt % Vol % Wt % Vol % Wt %Vol % Wt % Vol % Wt % Vol % Wt % Vol % PP 7 100 100 90 78 69 62 65 58.365 58.3 65 58.3 GB1 — — 14 22 14 22 14 22.0 14 22.0 14 22.0 C1 — — — — —— 4 3.6 4 3.6 4 3.6 IM3 — — — — — — — — — — 17 16.1 IM2 — — — — — — — —17 16.1 — — IM1 — — — — 17 16 17 16.1 — — — — Density 0.90 0.817 0.8180.812 0.823 0.820 (g/cc) TS (Mpa) 18.2 11.1 8.9 12.6 12.8 12.9 TM (Mpa)917 1245 802 782 780 776 EL % 30 13 52 23 22 14 FS (Mpa) 26.0 20.7 15.019.2 19.0 19.4 FM @ % 866 1119 761 788 767 786 secant (Mpa) NI (J/m) 12841 125 260 300 250 notched D256 MFI (230° C. 55 27 22 17.6 18.5 13.12.16 kg) MFI/density 61.1 33.0 26.9 21.7 22.5 16.0 (1/g/cc)

Examples 26, 27, 28 and Comparative Examples 13A-13U

TABLE 17 CE13A CE13B CE13C EX 26 EX 27 EX 28 Wt % Vol % Wt % Vol % Wt %Vol % Wt % Vol % Wt % Vol % Wt % Vol % PP 8 100 100 90 78 69 62 65 58.365 58.3 65 58.3 GB1 — — 14 22 14 22 14 22.0 14 22.0 14 22.0 C1 — — — — —— 4 3.6 4 3.6 4 3.6 IM3 — — — — — — — — — — 17 16.1 IM2 — — — — — — — —17 16.1 — — IM1 — — — — 17 16 17 16.1 — — — — Density 0.90 0.824 0.8170.815 0.823 0.822 (g/cc) TS (Mpa) 15.9 10.0 8.8 10.2 10.0 10.5 TM (Mpa)846 993 530 640 578 577 EL % 33 34 130 52 71 83 FS (Mpa) 19.9 14.9 12.314.3 13.8 14.3 FM @ % 747 780 534 590 558 573 secant (Mpa) NI (J/m) 660153 125 381 423 455 notched D256 MFI (230° C. 18.9 8.6 8.8 8.4 8.8 6.72.16 kg) MFI/density 21.0 10.4 10.8 10.3 10.7 8.2 (1/g/cc)

Example 29 and Comparative Examples 13A, 13B, 14A

TABLE 18 CE13A CE13B CE14A EX 29 Vol Vol Vol Vol Wt % % Wt % % Wt % % Wt% % PP 8 100 100 90 78 70 63 66 59.4 GB1 — — 14 22 13 21 13 21.1 C1 — —— — — — 4 3.6 IM4 — — — — 17 16 17 15.9 Density (g/cc) 0.90 0.824 0.8190.824 TS (Mpa) 15.9 10.0 9.1 13.6 TM (Mpa) 846 993 864 865 EL % 33 34 3530 FS (Mpa) 19.9 14.9 14.9 19.4 FM @ % 747 780 779 802 secant (Mpa) NI(J/m) 660 153 233 316 notched D256 MFI (230° C. 18.9 8.6 5.3 5.8 2.16kg) MFI/density 21.0 10.4 6.5 7.0 (1/g/cc)

Example 30 and Comparative Examples 13A, 13B and 15A Correct Selectionof Compatibilizers

Table 19 demonstrates that the correct selection of C1 for PP7 (EX30)improves the impact strength vs. selecting C2 for PP7(CE15A). Thecompatibilizer is chosen such that the back bone where the functionalgrafts are attached can co-crystallize and compatible with the mainmatrix resin.

TABLE 19 CE13A CE13B EX 30 CE15A Wt % Vol % Wt % Vol % Wt % Vol % Wt %Vol % PF 7 100 100 90 78 65 58.3 64.7 58.2 GB1 — — 14 22 14.0 22.0 14.022.2 C1 — — — — 4.0 3.6 — — C2 — — — — — — 4.0 3.4 IM2 — — — — 17 16.117.3 16.2 Density (g/cc) 0.90 0.817 0.823 0.813 TS (Mpa) 18.2 11.1 12.89.6 TM (Mpa) 917 1245 780 590 EL % 30 13 22 43 FS (Mpa) 26.0 20.7 19.014.4 FM @ % secant (Mpa) 866 1119 767 543 NI (J/m) notched D256 128 41300 89 MFI (230° C. 2.16 kg) 55 27 18.5 18.4 MFI/density (1/g/cc) 61.133.0 22.5 22.6

Example 31, 32 and Comparative Examples 13A, 13B and 1SB PreferredAmount of Compatibilizers

Table 20 demonstrates that the preferred amount of compatibilizer forPP7 (EX30 and EX31) shows improved impact strength whereas lower amounts(CE15A) lower the impact strength compared to unfilled control resinCE13A and impact modifier containing with 0% compatibilizers only(CE12C) shown above. Preferred amount is between 2 and 4%.

TABLE 20 CE13A CE13B EX 30 EX 31 CE15B Component Wt % Vol % Wt % Vol %Wt % Vol % Wt % Vol % Wt % Vol % PP7 100 100 90 78 65 58.3 66.7 60.267.8 60.8 GB1 — — 14 22 14.0 22.0 14.0 21.8 14.0 22.2 C1 — — — — 4.0 3.62.1 1.9 1.1 0.9 IM2 — — — — 17 16.1 17.2 16.1 17.2 16.0 Density (g/cc)0.90 0.817 0.823 0.811 0.811 TS (Mpa) 18.2 11.1 12.8 12.6 11.9 TM (Mpa)917 1245 780 800 777 EL % 30 13 22 25 28 FS (Mpa) 26.0 20.7 19.0 17.917.1 FM @ % secant 866 1119 767 712 693 (Mpa) N1 (J/m) notched 128 41300 240 111 D256 MFI (230° C. 55 27 18.5 18.1 19.4 2.16 kg) MFI/density61.1 33.0 22.5 22.3 23.9 (1/g/cc)

Example 33, 34, 35 and Comparative Example CE16A, 13B and 15B PreferredAmount of Impact Modifier

TABLE 21 CE13A CE13B CE16A EX 33 EX 34 EX 35 EX 36 CE16B Wt % Vol % Wt %Vol % Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol %PP7 100 100 90 78 77.7 70.6 73.8 66.9 70.2 63.2 65 58.3 56.7 51.2 46.141.4 GB1 — — 14 22 14.0 21.7 14.0 21.7 14 22.3 14.0 22.0 14.0 21.5 14.021.4 C1 — — — — 4.0 3.6 4.0 3.6 4.1 3.6 4.0 3.6 4.0 3.6 4.1 3.6 IM2 — —— — 4.3 4.1 8.2 7.7 11.7 11.0 17 16.1 25.2 23.7 35.8 33.5 Density (g/cc)0.90 0.817 0.812 0.811 0.811 0.823 0.809 0.806 TS (Mpa) 18.2 11.1 16.614.9 14.7 12.8 10.4 8.2 TM (Mpa) 917 1245 1086 1040 940 780 623 355 EL %30 13 4 7 11 22 48 102 FS (Mpa) 26.0 20.7 25.5 23.6 21.6 19.0 14.6 10.1FM @ 1% 866 1119 990 937 850 767 590 385 secant (Mpa) NI (J/m) 128 41 83142 193 300 340 380 notched D256 MFI (230° C. 55 27 25.8 21.8 19.6 18.513.8 15.2 2.16 kg) MFI/density 61.1 33.0 31.8 26.9 24.2 22.5 17.1 18.9(1/g/cc)

Comparative Examples CE2A, CE17A, CE17B, CE17C, CE17D, CE2C and EX5Effect of Compatibilizer in the Absence of Glass Bubbles

Comparing CE17A to CE17B, one can see that the addition ofcompatibilizer to a compound with 20% polyolefin elastomer does notresult in further enhancement of the impact strength. In fact there is aslight reduction of impact strength.

Comparison of CE17A to CE17B also shows that compatibilizer have aneutral to negligible improvement (4% increase) effect on the impactstrength of a compound that contains 15.5 wt %/impact modifier.These results are contrary to what we see with glass bubble containingformulas where the correct selection of compatibilizer type and amountimprove the impact strength of a compound containing polyolefinelastomer (compare CE2C and EX5 with 30% increase in impact strength).

TABLE 22 CE2A CE17A CE17B CE17C CE17D CE2C EX 5 Wt % Vol % Wt % Vol % Wt% Vol % Wt % Vol % Wt % Vol % Wt % Vol % Wt % Vol % PP1 100 100 80 79.375.3 74.7 84.5 84.0 80.9 80.4 69 62 65 58.3 GB1 — — — — — — — — — — 1422 14 22.0 C1 — — — — 4.7 4.6 — —  3.6  3.5 — — 4 3.6 IM1 — — 20 20.7 2020.7 15.5 16.0 15.5 16.0 17 16 17 16.1 Density (g/cc) 0.9 0.894 0.9090.895 0.907 0.802 0.801 TS (Mpa) 29.2 21.0 23.2 23.2 25.6 13.9 19.1 TM(Mpa) 1190 756 878 859 965 900 1180 EL % limit limit limit limit limitlimit 14 FS (MPa) 37.6 23.6 28.7 26.5 31.8 23.8 28.9 FM @ 1% 1063 709849 808 977 970 1075 secant (MPa) NI (J/m) notched 48 246 216 147 153 4660 D256 MFI (230° C. 4.7 11.0 11.0 9.65 9.0 3.8 4.7 2.16 kg) MFI/density5.2 12.3 12.1 10.8 9.9 4.5 5.5 (1/g/cc)

This disclosure is not limited to the above-described embodiments but isto be controlled by the limitations set forth in the following claimsand any equivalents thereof. This disclosure may be suitably practicedin the absence of any element not specifically disclosed herein.

1. A composition comprising: a polyolefin comprising first repeatingunits; hollow glass microspheres; a polyolefin impact modifier that ischemically non-crosslinked and free of polar functional groups; and acompatibilizer comprising the first repeating units and second repeatingunits, which are the first repeating modified with polar functionalgroups, wherein the hollow glass microspheres are present in a rangefrom 40% to 70% by volume, the polyolefin impact modifier is present ina range from 20% to 50% by volume, and the compatibilizer is present ina range from 4% to 12% by volume, based on the total volume of thehollow glass microspheres, the polyolefin impact modifier, and thecompatibilizer, and wherein the composition has a notched izod impactstrength of at least 60 joules/meter, and wherein the compositioncomprises greater than ten percent by weight of the glass, based on thetotal weight of the composition.
 2. The composition of claim 1, whereinat least one of the following conditions is met: the tensile modulus ofthe composition is at least 50% of the polyolefin, or the tensilestrength of the composition is at least 50% of the polyolefin, or theflexural modulus of the composition is at least 50% of the polyolefin,or the flexural strength of the composition is at least 50% of thepolyolefin.
 3. A masterbatch composition for combining with a polyolefincomprising first repeating units, wherein the masterbatch comprises:hollow glass microspheres; a polyolefin impact modifier that ischemically non-crosslinked and free of polar functional groups; and acompatibilizer comprising the first repeating units and second repeatingunits modified with polar functional groups, wherein the hollow glassmicrospheres are present in a range from 40% to 65% by volume, thepolyolefin impact modifier is present in a range from 20% to 50% byvolume, and the compatibilizer is present in a range from 4% to 15% byvolume, based on the total volume of the hollow glass microspheres, thepolyolefin impact modifier, and the compatibilizer.
 4. The compositionof claim 1, wherein the polyolefin comprises at least one ofpolyethylene or polypropylene.
 5. The composition of claim 1, whereinthe first repeating units are polyethylene repeating units.
 6. Thecomposition of claim 1, wherein the polyolefin impact modifier has amelt flow index at 190° C. and 2.16 kilograms of at least 10 grams per10 minutes.
 7. The composition of claim 1, comprising greater than twopercent by weight of the compatibilizer, based on the total weight ofthe composition.
 8. The composition of claim 1, wherein thecompatibilizer is a maleic anhydride-modified polyolefin.
 9. Thecomposition of claim 1, further comprising reinforcing fillers.
 10. Thecomposition of claim 1, wherein the composition comprises less than fivepercent by weight talc, based on the total weight of the composition, orwherein the composition comprises less than one percent by weight of atleast one of montmorillonite clay having a chip thickness of less than25 nanometers or calcium carbonate having a mean particle size of lessthan 100 nanometers.
 11. The composition of claim 1, wherein the hollowglass microspheres are not treated with a silane coupling agent.
 12. Thecomposition of claim 1, wherein a hydrostatic pressure at which tenpercent by volume of the hollow glass microspheres collapses is at leastabout 50 megapascals.
 13. The composition of claim 1, wherein thepolyolefin impact modifier is an ethylene propylene elastomer, anethylene octene elastomer, an ethylene propylene diene elastomer, anethylene propylene octene elastomer, or a combination thereof.
 14. Anarticle comprising the composition of claim 1, wherein the compositionis a solid, wherein the article is a hardhat, or wherein the article isan interior or exterior automobile component.
 15. A method of making anarticle, the method comprising injection molding the composition ofclaim 1 to make the article.
 16. The composition of claim 1, wherein thepolyolefin is other than a polypropylene homopolymer.
 17. Thecomposition of claim 1, wherein the first repeating units arepolypropylene repeating units, and the compatibilizer comprisespropylene repeating units, and the polyolefin is a copolymer comprisingat least 80% by weight propylene unit or the polyolefin is a medium orhigh impact polypropylene.
 18. The composition of claim 1, comprisinggreater than three percent by weight of the compatibilizer, based on thetotal weight of the composition.
 19. The composition of claim 1, whereinthe polyolefin impact modifier is an ethylene octene elastomer.
 20. Thecomposition of claim 1, wherein the composition comprises at least tenpercent by weight of the glass, based on the total weight of thecomposition;